The Swan is a 1956 remake, directed by Charles Vidor, of a 1925 movie about the daughter of a minor branch of a European royal house who is being considered as a wife for her cousin, the heir to the throne. Grace Kelly is the princess, and the movie was made because she was about to become a princess in real life. Her cousin the crown prince is played by Alec Guinness, and her brothers' tutor, a commoner for whom she thinks she may feel more affection than she does for the prince, is played by Louis Jourdan.

The princess's relatives -- played by Jessie Royce Landis, Estelle Winwood, and Brian Ahern -- are comically eccentric, and Agnes Moorhead, as the queen who shows up near the end to find out if the princess has made the grade, is crankily imperious. Leo G. Carroll plays their butler.

The 1925 silent film with the same title was directed by Dimitri Buchowetzki and starred Frances Howard as Princess Alexandra and Adolphe Menjou as Crown Prince Albert.